Habib Diarra scored his second goal of the World Cup to put Senegal into a deserved lead in their round of 32 tie with Belgium.
Senegal qualified as one of the eight best third-placed teams having thrashed Iraq 5-0 in their final group game, while Belgium won Group G.
But it was the Lions of Teranga who dictated proceedings from the off in Seattle, with Ismaila Sarr seeing a close-range hit the post after Ismail Jakobs’ left-wing cross was palmed into his path by Belgium goalkeeper Thibaut Courtois.
Sarr was denied by the woodwork a second time in the 24th minute as his header from Sadio Mane’s delivery hit the same post, but this time Sunderland’s Diarra was on hand to tap in the rebound and put Senegal in front.
It marked Diarra’s second goal of the tournament, the midfielder having given Senegal the lead in the rout of Iraq.
Senegal are looking to reach the last 16 for a second successive World Cup, having lost to England at that stage in 2022.
Belgium went out in the group stage of that tournament, and Diarra’s goal left the Red Devils staring down the barrel of another early exit.
